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Advanced soſtware packages not only make trusses more accurate and cost effecve designs but also kick in a lot of design assumpons and limitaons such as truss to be installed straight and plumb, truss to be fully restrained at top chord and boom chord and so on. Once all of these design assumpons and limitaons are achieved, the designed trusses will performe to their full potenal and will be fit for purpose. APRIL 2019 - NO.11 Siu Kong Fox - Mulnail NSW Design Engineer TEMPORARY SUPPORT OF THE GIRDER TRUSS DURING THE INSTALLATION COULD SAVE FUTURE PROBLEMS Page 1 When carpenters start a truss installaon job, it is a common pracce that they install the girder truss first and load the carried trusses on so that the carried trusses are supported. We all know that girder trusses normally have bigger size and higher grade mber and are stronger than standard trusses, however, the carpenter doesn’t really know how strong they are, or the limitaons of achieving their full capacies. The photographs below show a Girder Truss spanning around 15m and carrying 8m span trusses. The girder is a triple truss, it is tall and appears to be a strong truss. But just look at the photo of the top chord buckling and you will realise that the word strong has its limitaons.
